The present invention relates to a device and method for minimizing toner consumption and preventing toner contamination in an image forming apparatus, and more particularly to a device and a method for allowing a user to select a preset paper size to be used in a manual paper feed mode and preventing printing in areas outside the preset range, thereby minimizing the toner consumption and preventing toner contamination in an image forming apparatus.
With an image forming apparatus, it is typical for a user to select sheets of paper that are suitable for use in a paper feed device (e.g., a paper cassette) of the apparatus. In these cases, a controller often detects the size of the paper, and image formation is performed in accordance with the detected size of the paper. An electrostatic latent image forming unit enables formation of an electrostatic latent image on an outer surface of a photosensitive dram in accordance with the size of the paper.
In general, when using paper in an image forming apparatus having a size that is other than a standard size, such as A4, Legal, or Letter, a manual paper feed device is used. This type of device is disclosed in U.S. Pat. No. 5,222,722 issued to Kamano on 29 Jun. 1993. In this type of conventional art, when paper is fed using a manual paper feed device, the image forming apparatus can not sense the width of the paper. Furthermore, image forming operations are performed regardless of the actual width of the paper fed through the manual paper feed device. Accordingly, if an electrostatic latent image formed on the photosensitive dram is actually smaller than the size of the paper fed to an electrostatic latent image forming device, there is no ostensible problem. However, if the electrostatic latent image formed on the photosensitive dram is actually larger than the size of the paper fed, a portion of the image developed by a developing unit is not able to be fully transferred onto the paper by a transfer unit, and a portion of unused toner remains on the photosensitive dram. This results in unnecessary toner consumption, as well as contamination of the image forming apparatus. As a result, the quality of printing eventually deteriorates.